Question

Solve the following system of equations. x − 2y = 5 −3x + 2y = 7 A. x = 3, y = −1 B. x = 11, C. x = −6, D. x = 3, y = 1

Answer 1

x - 2y = 5
-3x + 2y = 7
-----------------add
-2x = 12
x = 12/-2
x = -6

-3x + 2y = 7
-3(-6) + 2y = 7
18 + 2y = 7
2y = 7 - 18
2y = - 11
y = -11/2

solution is : (-6,-11/2)...x = -6 and y = -11/2

Answer 2

Answer: C) x=-6

Explanation: we can solve a system of equation by different methods, in this case we will use substitution:

First we isolate the x from the first equation:

x=5+2y

then we replace it in the second equation:

-3x+2y=7

-3(5+2y)+2y=7

now we solve and isolate the y

-15-6y+2y=7

-15-4y=7

-4y=7+15

-4y=22

y=22/-4

y=-11/2

now we replace the value of y in the first equation:

x=5+2y

x=5+2(-11/2)

x=5-11

x=-6